Robot manipulators are widely used in many industrial automation applications. A robot manipulator moves the end-effector to the configuration instructed by the user. The user input from a master unit is transformed into the desired configuration through forward kinematics. This configuration is communicated to the robot controller, which employs inverse kinematics to transform the configuration into joint angles. The control algorithm is implemented as software and embedded into the robot controller. The software is typically written in traditional programming languages like C or C++. We introduce a Simulink Library ModelRob that provides basic building blocks to model kinematics of a robot manipulator. Availability of such a library enables Model-Based Development (MBD) of robot manipulator software where the manipulator controller can be modeled using ModelRob library blocks, and production code can be automatically generated using existing code generators for Simulink. We enlist the existing tools that will be useful in the verification and validation stage of the MBD process, and outline the need for tool-support for verification activities specific to building robust robot manipulator software. Using ModelRob library we have modeled Cartesian space motion controller of a robot manipulator in Simulink and successfully generated C code from the model.